How to manage label-based access control (Enterprise)

danger

This is an Enterprise feature. If the Memgraph Enterprise is not activated, all the created users will be granted all of the privileges.

Sometimes, authorizing the database by granting and denying clause privileges is not enough to make the database fully secure. Certain nodes and relationships can be confidential and must be restricted from viewing and manipulating by multiple users.

In response to the need for such authorization, Memgraph has advanced its authorization features to enable authorization on node labels and relationship edge types. By applying authorization to graph's first class citizens, a database administrator can now keep all the data in one database while keeping any private data secure from those who don't have adequate permission.

This how-to-guide will walk you through label-based access control in the use case of a fictional company doing data analytics and machine learning.

The fictional company's day-to-day business is ingesting new data for training machine learning models. Alice is the database administrator in the company, and she would like to set up label-based access control inside Memgraph to make data manipulation more secure.

When she tries out Memgraph the first time, she is connected to a session with all privileges and is able to create users and roles and grant them privileges. As a first task, she creates the admin role, which is automatically granted permission to write any clause and access any node or relationship.

CREATE USER admin IDENTIFIED BY 'PaSsWoRd';

The user admin is also able to verify that she has all the privileges by writing:

SHOW PRIVILEGES FOR admin;

privilege	effective	description
CREATE	GRANT	GRANTED TO USER
DELETE	GRANT	GRANTED TO USER
MATCH	GRANT	GRANTED TO USER
MERGE	GRANT	GRANTED TO USER
SET	GRANT	GRANTED TO USER
REMOVE	GRANT	GRANTED TO USER
INDEX	GRANT	GRANTED TO USER
STATS	GRANT	GRANTED TO USER
AUTH	GRANT	GRANTED TO USER
CONSTRAINT	GRANT	GRANTED TO USER
DUMP	GRANT	GRANTED TO USER
REPLICATION	GRANT	GRANTED TO USER
READ_FILE	GRANT	GRANTED TO USER
DURABILITY	GRANT	GRANTED TO USER
FREE_MEMORY	GRANT	GRANTED TO USER
TRIGGER	GRANT	GRANTED TO USER
CONFIG	GRANT	GRANTED TO USER
STREAM	GRANT	GRANTED TO USER
MODULE_READ	GRANT	GRANTED TO USER
MODULE_WRITE	GRANT	GRANTED TO USER
WEBSOCKET	GRANT	GRANTED TO USER
ALL LABELS	CREATE_DELETE	GLOBAL LABEL PERMISSION GRANTED TO USER
ALL EDGE_TYPES	CREATE_DELETE	GLOBAL EDGE_TYPE PERMISSION GRANTED TO USER

If you want to find more about user privileges, hover over to Managing user privileges

Alice can now log in as an administrator in Memgraph with her own account. From that point on, she can also create new users and roles in the database. The subsequently created users and roles won't have any privileges or label-based permissions and need additional commands to be granted permissions to the clauses and the graph.

Granting read permissions

Bob is a data analyst for the company. He is making sure he can extract any useful insights from the data imported into the database. For now, all the data is labeled with the DataPoint label. Alice has already created a data analyst role as well as Bob's account in Memgraph with:

CREATE ROLE analyst;
CREATE USER Bob IDENTIFIED BY 'test';
SET ROLE FOR Bob TO analyst;

Unfortunately, when he writes:

MATCH (n:DataPoint) RETURN n;

he gets an error that he can not execute the query. Why is that? The first problem that we encounter is that Bob can not perform MATCH queries, which we must explicitly grant.

The database administrator grants him and all the data analysts the MATCH query to traverse the graph with:

GRANT MATCH TO analyst;

Now Bob is able to perform a match. However, by executing the same query again, he is not able to get any results. Now that's unfortunate. Did we do anything wrong?

Enter label-based access control. Since Bob is not an administrator, he was not able to see any data points in the graph. In other words, he does not have READ permission on the DataPoint label.

Memgraph's label-based access control is hierarchically constructed, and the first permission one can be given on node labels or relationship edge types is READ.

Alice now updates Bob's permissions by executing:

GRANT READ ON LABELS :DataPoint TO analyst;

Bob is now executing his queries normally and is able to get insights from the database with respect to all the data points in the graph!

Additionally, in the company, it was decided that all the data points would be connected in a time series fashion, depending on when they were ingested into the database. One DataPoint should therefore be connected to the previously inserted one. The relationship type is called :NEXT.

Bob now again has problems, because when he executes:

MATCH (n:DataPoint)-[e:NEXT]->(m:DataPoint);

he is not able to see the patterns. Although Bob can see all the data points, he doesn't have permission to view the relationships. The database administrator executes the following command to solve the problem:

GRANT READ ON EDGE_TYPES :NEXT TO analyst;

Since the users are initially constructed without any permission, they would need an explicit grant for every new label that appears in the database. This approach is called whitelisting, and is more secure for adding new entities in the database since confidential nodes and relationships are not leaked into the database before securing them.

We have now gone through the READ permissions for the first class graph citizens. Let's move on to a different role in the company.

Granting update permissions

Charlie is a tester and customer care specialist. He is in charge of reporting bugs and fixing issues in the database. A common problem that he is facing is updating the classes of the data points if they are labeled incorrectly. For example, the class of one DataPoint might be 'dog', while in fact it is an 'elephant', but it was wrongly selected in the rush of labeling many data points. Charlie needs to update the wrongly labeled data points, and he already has the IDs of all the nodes he must update.

Alice has already set up his account with the following commands:

CREATE ROLE tester;
CREATE USER Charlie IDENTIFIED BY 'test';
SET ROLE FOR Charlie TO tester;

GRANT MATCH, SET TO tester;

GRANT READ ON LABELS :DataPoint TO tester;
GRANT READ ON EDGE_TYPES :NEXT TO tester;

He now has read privileges just like all the data analysts, but when he gets an authorization error while executing:

MATCH (n:DataPoint {id:505}) SET n.labelY = 'elephant';

The error occurs because Charlie does not have permission to update the existing nodes in the graph. The database administrator needs to update Charlie's permissions and grant him access to update the node properties with:

GRANT UPDATE ON LABELS :DataPoint TO tester;

Charlie is now able to update the labeled categories of any data point in the graph! The same permission applies if he needs to update a relationship property in the graph.

Granting full access permissions

David is the data engineer for the company. He is very skilled in database systems, and he has been assigned the task of deleting every data point in the system that's older than one year. Alice has his account set up with the following commands:

CREATE ROLE dataEngineer;
CREATE USER David IDENTIFIED BY 'test';
SET ROLE FOR David TO dataEngineer;

GRANT MATCH, DELETE TO dataEngineer;

GRANT UPDATE ON LABELS :DataPoint TO dataEngineer;
GRANT UPDATE ON EDGE_TYPES :NEXT TO dataEngineer;

However, UPDATE privilege capabilities only grant manipulation of properties, not the nodes and relationships themselves. Therefore, the query:

MATCH (n:DataPoint) WHERE localDateTime() - n.date > Duration({day:365}) DETACH DELETE n;

results in an error. The permission that grants read, update, create, and delete rights over the nodes and relationships in the graph is CREATE_DELETE. By executing the following commands:

GRANT CREATE_DELETE ON LABELS :DataPoint TO dataEngineer;
GRANT CREATE_DELETE ON EDGE_TYPES :NEXT TO dataEngineer;

The permission is executed on relationships as well, since David needs to detach the nodes prior to deleting them. David is now able to successfully delete the deprecated nodes.

Denying visibility

Eve is the new senior engineer in town, and she is making excellent progress in the company. The management therefore decided to grant her visibility and manipulation over all the nodes. However, there are certain confidential nodes that are only for the management people to see.

Since there could be a lot of different node labels or relationship types in the database, a shortcut can be made by granting NOTHING to the entity. The database administrator therefore sets Eve's role as:

CREATE ROLE seniorEngineer;
CREATE USER Eve IDENTIFIED BY 'test';
SET ROLE FOR Eve TO seniorEngineer;

GRANT MATCH, DELETE TO seniorEngineer;

GRANT CREATE_DELETE ON LABELS * TO seniorEngineer;
GRANT NOTHING ON LABELS :SecretLabel TO seniorEngineer;

When granting NOTHING, the user is denied both visibility and manipulation of the entity. Eve is now able to see all the domain data while the management is happy since they have not leaked any confidential data.

Templates for granting privileges

To grant all privileges to a superuser (admin):

GRANT ALL PRIVILEGES TO admin;
GRANT CREATE_DELETE ON LABELS * TO admin;
GRANT CREATE_DELETE ON EDGE_TYPES * TO admin;

To grant all read and write privileges:

DENY ALL PRIVILEGES TO readWrite;
GRANT CREATE, DELETE, MERGE, SET, REMOVE, INDEX, MATCH, STATS TO readWrite;
GRANT CREATE_DELETE ON LABELS * TO readWrite;
GRANT CREATE_DELETE ON EDGE_TYPES * TO readWrite;

To grant read only privileges:

DENY ALL PRIVILEGES TO readonly;
GRANT MATCH, STATS TO readonly;
GRANT READ ON LABELS * TO readonly;
GRANT READ ON EDGE_TYPES * TO readonly;

Where to next?

To learn more about Memgraph's functionalities, visit the Reference guide. For real-world examples of how to use Memgraph, we strongly suggest going through one of the available Tutorials.